class_docstr: Swap-in HDF5 File Handler.
docstr: Return copy of dataarray to prevent manipulating attributes in the original.
docstr_tok: ["Return","copy","of","dataarray","to","prevent","manipulating","attributes","in","the","original","."]
code: def __getitem__(self, key):
      """Return copy of dataarray to prevent manipulating attributes in the original."""
      val = self.file_content[key]
      if isinstance(val, xr.core.dataarray.DataArray):
          val = val.copy()
      return val
  
imports: import os
  import unittest
  from unittest import mock
  import dask.array
  import numpy
  import pytest
  import xarray
  from satpy.tests.reader_tests.test_hdf5_utils import FakeHDF5FileHandler
label_desc: Use image node_id 1 for calling the FakeHDF5FileHandler2 obj's underlying member method code with example usage: obj.__getitem__(key) and returns: val